Pulverizing or grinding mill



April 1, 1930. UHLE ET AL 1,752,622

PULVERIZING OR GRINDING MILL Filed March 30, 1928 2 Sheets-Sheet l DAVID J UHLE 3 JOEPH V. DURNlN, v

A TTORNEY.

Patented Apr. 1, 1930 UNITED STATES PATENT OFFICE DAVID J. UHLE AND JOSEPH V. DUBNIN, F ALLENTOWN, PENNSYLVANIA PULVERIZING 0R GRINDING MILL Application filed March 30, 1928.

Our invention relates to improvements in pulverizing or grinding mills, and has particular reference to improvements in the rotatable yoke of such mills.

In accordance with our invention, a rotatable yoke is provided which is secured to and driven by the usual drive shaft. This yoke has radial arms carrying slidable pusher elements, which engage against springs. The

1C:- pusher elements have spherically curved ends, to engage with the grinding balls. Means are provided to prevent the pusher elements from turning upon their longitudinal axes. The yoke is provided with an upper set of radial arms, upon which is rigidly attached an annular blade carrying ring. The construction of the yoke and associated elements is simple, compact, and highly eflicient.

In the accompanying drawings, forming a part of this specification, and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a central vertical longitudinal section through a mill embodying our invention,

Figure 2 is a horizontal section taken on line 2-2 of Figure 1,

Figure 3 is a similar view taken on line 3-3 of Figure 1,

Figure 4 is a plan view of the yoke and associated elements,

Figure 5 is a side elevation of the same,

Figure 6 is an enlarged fragmentary plan view of one of the radial arms of the yoke 35 and the pusher element, I

Figure 7 is a side elevation of the same, and,

Figure 8 is a longitudinal section taken on line 88 of Figure 7.

The yoke and associated elements constitutec ing the principal feature of the present invention, are articularly adapted for use in connection with the pulverizing or grinding mill, shown in, Letters Patent No. 922,468, .granted under. date of May 25, 1909 to J. W.

:5 Fuller, J r. The mill embodies generally a casing 10, within which is arranged a grinding ring 11, having a transversely curved annular recess 12', within which travels the grinding balls 14. An upper casing section 50 15 is arranged upon the casing 10, and a screen Serial No. 266,030.

16 is disposed within the casing section 15 and spaced therefrom, with a coarser protecting screen 17 disposed inwardly of the first named screen. The pulverized or ground material which passes the screen 16 discharges into a passage 18, and descends through the passage 19 and finally discharges through an outlet 20. The numeral 21 designates a feed hopper, which discharges the material into the upper portion of the casing 15, inwardly of the screen 17.

The numeral 22 designates a vertical drive shaft, journaled in bearings 23 and 24, and driven by a pulley 25. As this construction is identical with that shown in Patent No. 922,468, above referred to, this description is thought to be sufficient.

Our improved yoke embodies a tubular hub 26, arranged upon the drive shaft 22 to rotate therewith. Radiating from the lower end of the hub are spaced horizontal arms 27, integral therewith. These arms have transverse recesses 28, which are preferably cylindrical, and receive bushings 29. I Mounted to slide within each bushing 29 is a cylindrical pusher element 30, the outer or forward end of which is spherically curved, as shown at 31, for sliding contact with the adjacent ball 14. The pusher element 30 is provided with a reduced stem 32, passing through a contracted I opening 33 in the arm. This reduced stem provides a shoulder 34. A compressible coil spring 35 surrounds the stem 32 and is arranged within the recess 28, and engages the shoulder 34,'to force the pusher element 30 forwardly. A lubricating opening 36 is provided in the top of the arm 27 and is closed by a plug 37. In order that the pusher element 30 may not turn upon its longitudinal axis, it is providedat its rear end with a transverse opening or slot 38, receiving a locking key 39, provided at its ends with heads 40. This key is adapted to be held within a groove 41, formed in the rear side of the arm 27 This rear side has beveled faces 42, as shown.

The upper end of the hub 26 of the yoke is preferably beveled, as shown at 43, to deflect material to be ground toward the grinding balls 14. Formed integral with the hub 26 near the upper end thereof are spaced horizontal radial arms 44, arranged at an elevation above the arms 27, and staggered with relation thereto.

The numeral designates a fan or blower as a whole, including a lower ring 46, carrying outwardly projecting radial lugs 47, bolted to the arms 44, as shown at 48. Formed integral with the ring 46 are spaced vertical arms 19, carrying upper vertically arranged blades or paddles 50, integral therewith. The blades are disposed at the leading edges of the vertical arms 49 an d are further connected therewith by tapered webs 51, integral therewith. The vertical blades 50 rotate adjacent to the screens 16 and 17 and serve to throw the ground material through or toward the same. The numeral 52 designates lower elevating blades or paddles which are inclined and have their lower ends extending in an elevation beneath the lower ends of the vertical blades 50. The lower elevating blades 52 are preferably provided at their outer edges with upstanding longitudinal flanges 53. The blades 52 are formed integral with the ring H3, and webs 53 reinforce and connect these parts, and are formed integral therewith. The elevating blades 52 operate above and near the grinding balls 14 and serve to raise the powdered or ground material, which is brought into the path of travel of the vertical centrifugal blades 50 and thrown thereby toward the screen 16.

In the operation of the mill, the material is fed into the central portion of the same through the hopper 21 and passes to the grinding balls 14, traveling upon the grind* ing ring 11. The shaft 22 is driven at a suitably high speed, and the elevating blades 52 serve to draw the ground. or powdered material upwardly and through the same into the path of travel of the vertical or centrifugal blades 50, which in turn throw the same toward or through the screens 16 and 17. It is thought that no further detailed description of the operation of the machine is necessary in view of Patent No. 922,468, above referred to.

It is to be understood that the form of our invention, herewith shown and described, is to be taken as'a preferred example of the same, and that various changes in the shape, size and arrangement of parts, may be resorted to without departing from the spirit of our invention, or the scope of the subjoined claims.

Having thus described our invention, we claim:

1. In a grinding mill, a casing, a grinding ring arranged within the casing, grinding balls operating upon the grinding ring, a drive shaft extending between the grinding balls, a yoke carried by the drive shaft and embodying generally radial arms having transverse Openings, longitudinally slidable pusher elements mounted to slide within the transverse openings and having faces to contact with the grinding balls, and springs within the openings and engaging the pusher elements to force them forwardly.

2. In a grinding mill, a casing, a grinding ring within the casing, grinding balls operating upon the grinding ring, a drive shaft extending between the grinding balls, a yoke carried by the drive shaft and having generally radial arms provided with transverse openings and also having grooves upon their rear faces, pusher elements slidable within transverse openings and having spherically curved faces to engage the balls, springs within the openings and engaging the pusherelements to force them forwardly, and keys carricd by the rear ends of the pusher elements and operating within the grooves to prevent the pusher elements from turning upon their longitudinal axes.

3. In a grinding mill, a casing, a grinding ring within the casing, grinding balls operating upon the gringing ring, a drive shaft extending between the grinding balls, a yoke carried by the drive shaft and having generally radial arms provided with transverse openings and also having grooves upon their rear faces, pusher elements mounted to slide within the transverse openings and having spherically curved faces to engage the grinding balls, said pusher elements being provided near their rear ends with transverse slots and keys having heads at their ends and inserted within transverse slots of the pusher elements and operating within said grooves to prevent the pusher elements turning upon their longitudinal axes, and springs to force the pusher elements forwardly.

4. In a grinding mill, a casing, a grinding ring within the casing, grinding balls operating upon the grinding ring, a drive shaft extending between the grinding balls. a yoke carried by the drive shaft and provided with generally radial arms having transverse recesses, each recess being open at its forward end and having a bottom wall at its rear end provided with a contracted opening, a longitudinally slidable pusher element mounted within each recess, a contracted stem secured to the pusher element and extending through the recess and through the contracted opening in said bottom wall, said stem forming a shoulder with the pusher element, a compressible coil spring arranged within the recess and surrounding the stem and confined be' tween the bottom wall and said shoulder, the spring being entirely enclosed within the recess, said pusher element being arranged to engage with the adjacent grinding ball and means whereby the pusher element is held against turning. movement upon its longitudinal axis, throughout a portion of its sliding longitudinal movement.

5. In a grinding mill, a casing, a grinding ll 1 ring within the casing, grinding balls operating upon the grinding ring, a drive shaft extending between the grinding balls, a yoke carried by the drive shaft and provided with generally radial arms having transverse recesses, each recess being open at its forward end and having a bottom wall at its rear end provided with a contracted opening, a longitudinally slidable pusher element mounted within each recess, a contracted stem secured to the pusher element and extending through the recess and through the contracted opening in said bottom wall, said stem forming a shoulder with the pusher element, a compressible coil spring arranged within the recess and surrounding the stem and confined between the bottom wall and said shoulder, the spring being entirely enclosed within the recess, said pusher element being arranged to engage with the adjacent grinding ball, and means to limit the forward movement of the pusher element with relation to the arm.

6. In a grinding mill, a casing, a grinding ring within the casing, grinding balls operating upon the grinding ring, a drive shaft extending between the grinding rings, a yoke carried by the drive shaft and having generally radial arms provided with transverse recesses, each recess being 0 en at its forward end, a longitudinally slida 1e pusher mounted within each recess and having a shoulder, a spring arranged within the recess and engaging the shoulder to force the pusher element forwardly, the pusher element being arranged to engage with the adjacent grinding ball and the spring being free from engagement with the grinding ball, and means to limit the outward movement of the pusher element.

7. In a grinding mill, a casing, a grinding ring within the casing, grinding balls operating upon the grinding ring, a drive shaft extending between the grinding rings, a. yoke carried by the drive shaft and having generally radial arms provided with transverse recesses, each recess having its forward end open and provided at its rear end with an opening, a longitudinally movable pusher element slidably mounted within the recess and having a part extending through the opening at the rear end of said recess, and a spring arranged within the recess and engaging the pusher element to force the same forwardly, said pusher element being arranged to engage the adjacent grinding ball and the spring being free from engagement therewith.

In testimony whereof we aflix our signatures.

DAVID J. UHLE. JOSEPH V. DURNIN. 

